aws emr put-auto-scaling-policy
Creates or updates an automatic scaling policy for a core instance group or task instance group in an Amazon EMR cluster. AWS CLI reference
3 options Its page in the AWS CLI reference
Options
--auto-scaling-policySpecifies the definition of the automatic scaling policy.--cluster-idSpecifies the ID of a cluster.--instance-group-idSpecifies the ID of the instance group to which the automatic scaling policy is applied.